The Siesta Sisters Imperial Guard Corps are bunny-girl weapons who can only be summoned by witches and sorcerers with a substantial amount of summoning skills. They attack using bows of light that fire potent beams of light which kill instantly on impact; the lone exception being Battler due to his invincible anti-magic shield. It is said that there is no escape from the Siestas' attacks, and they can even locate targets from far parts of the island and retrieve the corpses of whom they've killed; despite this, the Siestas appear to be far from fearless, being terrified away twice when it appeared that their attacks had been useless against both Beatrice and Battler in Banquet of the Golden Witch. They have red eyes, bunny ears, and elaborate military-styled outfits.

It is hinted that they are connected to Maria in many different ways: Maria owns a set of ceramic musician rabbit toys said to wear uniforms resembling theirs; they bear a cross-shaped crest on their left arms, which resembles the last character in Maria's name, "a" ; and they are highly protective of Maria when she is around and willing to carry out her orders, such as during the Tea Party of Banquet of the Golden Witch. The only known witches and sorcerers who have been able to summon the Siestas are Eva-Beatrice, Goldsmith, and Erika Furudo. Beatrice can also summon them, but she has only done so in the Beatrice's White Day TIPS. Their true master is referred to as Pendragon, or the "Dragon King", who is only mentioned by name.